Carbon dots-melatonin-chitosan coating to alleviate chilling injury, enhance storage quality and antioxidant capacity of yellow peaches

Abstract

Carbon dots-melatonin-chitosan (CDs+MT) coatings at concentrations of 0.1 %, 0.2 %, 0.3 %, and 0.4 % to alleviate chilling injury (CI), enhance storage quality and antioxidant capacity of yellow peaches during 28 d of storage at 4 ℃ were investigated. The results indicated that the CDs+MT coating presented a more compact structure, with a characteristic peak at 22.3° corresponding to chitosan-based coating. CDs+MT coatings exhibited excellent antioxidant activity and antimicrobial properties. Especially, the preservation effect of 0.3 %CDs+MT treatment on yellow peaches was better than that of other treatments. After 28 days, compared with the control group, the CI of the 0.3 %CD + MT processing group was 7.23 times lower, the hardness was 7.71 times higher, the weight loss rate was 2.6 times lower, the ASA content was 1.42 times higher, the MDA content was 1.70 times lower, the number of bacteria was 79.45 times lower, the number of fungi was 19.06 times lower, and the scavenging rate of free radicals of DPPH and ABTS was higher respectively by 2.67 and 1.24 times. Moreover, CDs+MT coatings improved antioxidant capacity, superoxide dismutase, catalase and peroxidase activities in yellow peach. Therefore, CDs+MT treatments have a promising application in CI alleviation and quality preservation of yellow peaches.